The present invention relates generally to convertible roofs for automobile vehicles and more specifically to a mechanism to tension a convertible roof.
Vehicle soft tops or pliable convertible roofs, hereinafter referred to as pliable roofs, are commonly supported using a plurality of cross-car elongated support members, or “roof bows”. The roof bows are commonly connected to the vehicle by a top stack assembly, having links, rotating connections and support elements. To tension, the pliable roof is often raised from a folded or stowed position until a forward-most roof bow is adjacent the vehicle windshield structure. The pliable roof or forward-most roof bow is latched to the vehicle windshield structure. A rear-most roof bow is commonly connected to a rear structure of the vehicle. For power actuated pliable roofs, an intermediate roof bow is commonly connected to an actuator, such as a hydraulic or mechanical actuator. The actuator rotates the connected roof bow and, via the top stack assembly, the remaining pliable roof sections to an upright and tensioned position. A disadvantage of these systems is the potential to damage the pliable roof by over-rotation or under-rotation of the powered intermediate roof bow. Still another disadvantage is that a backlite section positioned in the rear of the pliable roof can be under-tensioned causing the backlite to vibrate during travel.
In accordance with the preferred embodiment of the present invention, a convertible roof actuation mechanism includes at least a forward bow, a power actuated rearmost bow and an intermediate bow, having a linkage set connecting the rearmost bow to the intermediate bow. In another aspect of the present invention, when the forward bow is latched and as the rearmost bow is rearwardly rotated, the linkage set rotates the intermediate bow to tension the roof cover.
In another embodiment, a pliable roof cover is supported by a plurality of roof bows. A linkage set connectably joins a rear-most bow to an intermediate bow. After a forward-most bow is connected to a vehicle windshield structure, the rear-most bow is positioned adjacent to a vehicle rear structure by an actuator device. The linkage set rotatably positions the intermediate bow in a roof cover tensioned position. In yet another embodiment, a convertible roof tensioning system includes five roof bows and a linkage set connecting a number four bow to a powered number five bow. In still another embodiment, a method to tension a convertible roof cover is provided.
The invention offers several advantages. A linkage set connecting a rearmost roof bow to a next adjacent roof bow allows the powered actuation of the rearmost roof bow to position the next adjacent roof bow, thereby tensioning the roof. All further forward roof bows can be pre-positioned and a forward-most bow latched to windshield structure prior to location of the rearmost bow and tensioning of the pliable roof. Further areas of applicability of the present invention will become apparent from the detailed description and claims provided hereinafter, taken into conjunction with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.